Help. Getting back on the road.

[gggGary]

Yes the LH carb is almost always the leaker when on the side stand. Even with working petcocks, the RH carb lets air in the lines, while the LH is busy drooling fuel 'til all the fuel in the lines has drained. This can happen even with good float valves, My guess; after shut off engine heat evaporates fuel from the float bowls, enough that both float valves will open slightly setting up the slow fuel line drain down.
Viton tipped float needle experiment coming soon, to a set of BS38's living here.

 

[gggGary]

The viton tipped Keihin float needles came in.
Check the pics, best description is "will fit"
stocker 14.61mm long 5.11mm wide
Keihin 15.43mm long 5.15mm wide
fit in the valve body seems OK
Note the increased angle on the float tang, worrisome? Might cause more float sticking? Kinda what we're trying to get a way from.
Maybe I'll rebuild a set of 78-79 with these in an see how they work.
But don't hold your breath while waiting...

 

[TwoManyXS1Bs]

Nice pics, gggGary.
Zooming in....

The float tab does have a bad angle.


Easily fixed by bending into an "S" shape.


My experience has been that the plunger pin is solid metal, the spring is within the valve body.


About 1mm *could* be ground off.


But, with the taller body, the plunger travel will be significantly reduced, and could affect dynamic (running, in motion) float height.

Also, note that the Viton tip is a 70° angle.


It won't set as deeply, and sealing will be concentrated at the upper edge of the float seat. Maybe not a bad thing, it shouldn't get stuck in the closed position...

 

[gggGary]

Very good points 2M!

 

[mrtwowheel]

That 70* point, vs 60* point, would add even more length to the valve when installed. I really like the idea of a Viton point. I like the squishiness of them and how they form to the seat to make more contact/seal. A little distortion of the Viton is a good thing, if installed in the same orientation every time. Like molding and forming your own valve, HELL YEAH!!!!!

Come on Gary, show us how to do this, Please?

Scott

 

[mrtwowheel]

HEY, most drill bits have a 60* point, any chance that a 70* bit could be found or fabricated to alter the valve seat?

Scott

 

[Mailman]

When I bought my 77D and first went through the carburetors, I had one float needle that looked just like that Keihen. I remember 5Twins pointing that out to me and saying he wasn’t sure where that came from.
Probably somebody experimenting like you.
I’m very interested in your results

 

[joebgd]

If I remember correctly, the needle valve on my 80 has soft rubber type of material tip. I put bigger jets years ago. Everything except the needle jet. The threads on the new needle jet weren't correct for the mains. I'm on the way to back off a little on the jet seizes. Ill check next time I'm in the carbs.

 

[gggGary]

If I remember correctly, the needle valve on my 80 has soft rubber type of material tip. I put bigger jets years ago. Everything except the needle jet. The threads on the new needle jet weren't correct for the mains. I'm on the way to back off a little on the jet seizes. Ill check next time I'm in the carbs.

yes the BS34's come with the rubber tip needles finding drop in one for the BS38's is the elusive goal.

 

[mrtwowheel]

yes the BS34's come with the rubber tip needles finding drop in one for the BS38's is the elusive goal.

The question on my mind is...….What purpose does the spring loaded float needles serve? Does a replacement needle have to be spring loaded? I could see a set of valve seats and matching Viton tipped valve needles being a good product to sell. See, there is an incentive to make this work, for somebody, there is an opportunity there.

Scott

 

[gggGary]

The question on my mind is...….What purpose does the spring loaded float needles serve? Does a replacement needle have to be spring loaded?
Scott

spring loaded; I think this is a vibration thing... prolly not an issue on an XS650...........
I have ended up with non spring loaded needles while bottom fishing carb kits, didn't even think of using them.

 

[5twins]

I think all float needles have that spring loaded pin. Something has to "give" a little in the set-up, what with fuel sloshing around and the levels always changing. A solid float needle might end up bending the float tang and throwing the float level setting off.

 

[mrtwowheel]

A solid float needle might end up bending the float tang and throwing the float level setting off.

I don't think the pressure is ever that great to bend the float tang. Wouldn't it be nice to have a big variety of needles to try? This is getting interesting, or just maybe something that I can wrap my head around, a nice break from electrical problems.

Scott

 

[joebgd]

Clutch cable broke. Need a new one asap. I really trust oem if anyone has a link or know where I can order one from.
I do need shocks and other bits from Mike's. Can I trust his clutch cable?

Also I'm finally getting new shocks, I like the ones w the red springs Mike's has but they are almost half inch longer than stock. Are there any advantages or disadvantages to that. I also like the all chrome slim line looking ones but they don't have progressive springs. So same question, adv... or diss.. to not having progressive springs.
I prob will go with the chrome cap ones w progressive springs that are the stock size.
Can I take a shock apart and put original shrouds on new ones and possibly paint the springs?

 

[TwoManyXS1Bs]

I think all float needles have that spring loaded pin. Something has to "give" a little in the set-up, what with fuel sloshing around and the levels always changing. A solid float needle might end up bending the float tang and throwing the float level setting off.

Some of our smaller Hondas had solid float needles. On bigger carbs, there's the risk of "battering" the valve seat, hence the spring plunger...

 

[Superjet]

Motion Pro for cables

 

[5twins]

Yes, Motion Pro has the best clutch cable. The one from Mike's, and now an O.E.M. one as well, has a smaller diameter inner wire. They don't last very long. The one from Mike's has been reported to break in as little as 400 miles. Best deal is usually from Amazon .....

https://www.amazon.com/76-81-YAMAHA-XS650-Motion-Standard/dp/B000OO0WT6

Slightly longer than stock rear shocks is a common and recommended upgrade. You won't get good shocks for $89 to $100, you'll need to spend more than that. That pretty much rules out any from Mike's. Yes, you can take shocks apart but you'll need a spring compressor of some sort.

 

[joebgd]

I wound up doing some searching and ordering a motion pro and a cast lever from an eBay store. My oem cracked and broke the barbell at the hand lever. The cable itself looks fine.
Good info on the shocks I'm going to wait a bit on that now.

 

[joebgd]

I won't have my new clutch cable for couple days.
I put on anew Jc Whitney hd 530 chain. Honestly idk if I trust it. I had one break on me in the past and the pins are smaller than stock I believe. Anyone have used this?
I was thinking ab bending my work actuator but decided no. It looks kind of robust and my clutch is not as hard as I hear of others. Also I think yamaha was refining as they went because if you look where rg drilled a new hole in actuator arm, that is where the hole in mine is originally closer to center f arm than end. Post 58 of Clutch worm actator...and tidbits. I believe it's in tech.

 

[5twins]

I used a JC Whitney HD chain for nearly the first 10 years I had my 650. It worked fine and served me well. When it came time to replace it, I went with something a bit better, a D.I.D. standard chain (not o-ring). The D.I.D. is supposed to be one of the best standard chains out there and can be had for around $40 if you shop around. Personally, I don't feel the need for a fancy, expensive o-ring chain on the 650, it's not that big and powerful.